There hasn't probably been so much to fix so far considering the damage level isn't overly high during these local fights. But yeah, I imagine some maintenance should be done all the time, after all, plastic isn't overly tough intrinsically leading to material fatigue if nothing else. It's a pity the series is skipping it as if it didn't matter. So far even Fumina might have been able to take care of Burning Gundam, but from now on it would take an expert since the national level contests (and above) use a high damage level.